''' P .ip . „ , . _ Water Resources Research Institute Oregon . State University Corvallis, Oregon . 1tiow,;, ..I.. .14 LIMNOLOGICAL STUDIES ON LAKES IN TH E DF-SCI3UTES NATIONAL .FORES-T, OREGON F . T . ODELL LAK E by Douglas W . Larson Department of Fisheries and Wildlife Oregon State University Corvallis, . Oregon 9733 1 WATER RESOURCES RESEARCH INSTITUT .E- CONTENTS ' Introduction 3 Lake Description- -Physical Features 5 Lake Description--Chemical Features . 1 5 Limnetic Phytoplankton Productivity 1 8 Conclusions 3 0 References 3 3 Distribution limited . Copies of this report may be obtained from th e Water Resources Research Institute . Single copies are free . This study was funded by the U . S. Department of the Interior, Offic e of Water Resources Grant No . 14-31-0001-3067 . INTRODUCTION Odell}. Lake, situated at the summit of the Cascade Range in the Deschutes National Forest, Oregon, serves various interest groups , including those that fish, camp, boat and waterski . The lake is easily reached by Oregon State -Highway 58 which parallels, closely, the shore - line to the north and east . The U .S . Forest Service maintains five campgrounds and .thre e boating facilities in the Odell basin . The use of these has increase d at a- rate of about 9% per year(J .H . Nunan, U .S . Forest Service, Crescent, Oregon, personal-comm.) . All Forest Service toilet facilitie s are of the vault-type- with one exception, this being at the Pebble . Ba y campground . The vaults are pumped two or three times du,ring th e summer and fall and the contents_ are removed from the basin (J . H. .Nunan, . personal comm. .) . Included in the total development of . the lake are two privately owned resorts, a marina, and 67 summer homes, most of which ar e situated at the west end of the lake . The homes are occupied usuall y from May until September. Sewage wastes are removed by drainage - field or pit-type systems . These are located, as a rule, at least 6 0 m back from the shoreline and 30 m from any water course (-J . H . Nunan, personal comm. ) . Since 1965, angler use of . Odell Lake has nearly doubled . Cree l census data, collected by the State of Oregon Game Commission, sho w 3 that the number of boat hours spent on Odell Lake increased fro m 46, 000 in 1965 (Averett, 1966) to over 69, 000 in 1968 (S . Lewis, Stat e of Oregon Game Commission, personal comm .) . The purposes of this report are (1) to document the limnology of Odell Lake, particularly at a time when the lake has not yet been greatl y deteriorated by recreational development, (2) to record phytoplankto n standing stock and primary production measurements, most of whic h are thought to be unusually high for an "-oligotrophic" lake, and (3) t o provide physical, chemical,and biological data that will establish a reference point, allowing responsible state and federal agencies t o estimate periodically the effects of population impact on the Odell Lak e basin. I am indebted to Mr . J . Wagner, Department of Oceanography , Oregon State University for certain water analyses, Dr . R . Simon, Department of Fisheries and Wildlife, Oregon State University for us e of liquid scintillation counting equipment, Drs . H . C . Curl, Jr . and L . F . Small, Department of Oceanography, Oregon State University fo r making their laboratory facilities available and Dr . C . E . Borid, Depart- ment of Fisheries and Wildlife for use of certain limnological gear . Mr . J. H. Nunan, U .S . Forest Service, Crescent, Oregon, Dr . E. Taylor, Department of Geology, Oregon State University and Mr ;. S . Lewis, State of Oregon Game Commission supplied important infotrna- tion for which I am very grateful . I thank.Drs . J .R . Donaldson, , C . E . Bond, L .P .- Small and H . K: Phinney for reviewing the manuscrip t and providing useful suggestions . My special thanks go to Dr . H.K . Phinney who identified the phytoplankton . The conscientious field an d laboratory assistance of Mr . J . Malick, Mr . R . Mailloux, Mr . G . McCoy, Mr . R . Lindland and Dr . R . Averett .was much appreciated . LAKE DESCRIPTION - PHYSICAL FEATURE S Geography and Geolog y Odell Lake is located approximately 174 km north of the Oregon - California border, and 180 km inland from the Pacific Ocean . The basin is thought to be a glacial trough closed at the eastern end" by a terminal moraine . The age of the basin is estimated at 10, 000 to 12, 000 years (E . Taylor, personal comm .) . During the eruptions of Mt . Mazama, volcanic ash was carrie d northward where it showered onto the loamy soils and ande.sitic lava in the Odell Lake basin . In time, a mantle of pumiceous ash and lapilli covered the basin to a thickness ranging from 35 to 150 cm . The mantle is coarsely textured and, therefore, is extremely permeable . Of the total volume of pumiceous material, 20% to more than 50% i s comprised of pebbles or "granules" (Wentworth, 1922) larger than 2 mm in diameter . The upper few inches is darkened by organic accumu- - lation. In places, particularly on high angle slopes, the mantle ha s been removed ' by weathering and mass-wasting to expose pre-existing soils and rock. Because of the texture of the surface layer, sheet - wash runoff is very slow or nonexistent . Subsurface percolation of water through pumiceous and loamy materials is very rapid ; thereb y facilitating the passage ofdissolved nutrients into the lake . Odell Lake is fed by two large, permanent tributaries (i .e . , Trapper and Crystal creeks)(Averett and Espinosa, 1968) . Both supply the lake with meltwater drained from higher elevations . On a map of Odell Lake, Newcomb_ (1941) indicated an additional 30 to 35 smalle r tributaries . Most of these are shown to enter the lake from the north . The major outlet tributary is Odell Creek which flows eastward for 1 3 miles until it -dischargea into Davis Lake (Averett and Espinosa, 1968) . Groundwater springs are known to exist along the south shoreline (Averett and Espinosa, 1968) . Climate Climatic data for the Odell Lake region was obtained from the- U .S. Weather Bureau (1965), and Phillips and Van Denburgh (1968) . For the period 1951 - 1960 (U .S. Weather Bureau, 1965), annual mean temperature was 5 .00 C . Total annual precipitation, includin g 8 1/3 meters of snowfall (yearly mean), averaged 152 .4 cm (U .S, Weather Bureau, 1965) . Phillips and Van Denburgh (1968) reporte d an annual mean precipitation of 156 . 1 cm in the period 1950 - 1964 . During 1968 (June - September), incident radiation averaged 241 .1 g 6 cal/cm2 /4 hra (1000 - 1400 hrs) . For the same period in 1969, th e 2 value was slightly less (i .e ., 236 .6 g cal/cm /4 hrs) . Morphometr y Morphornetric data for Odell Lake are presented in Table 1 . All values were computed from contour map no . 1274, State of Oregon Game Commission, Portland, Oregon (Figure 1) . As shown, the basin i s moderately elongated with a-U-shaped cross profile (features that iden- tify the basin as. .a glacial trough) . Maximum depth occurs at th e eastern end of the lake where .the slope of the basin wall is abrupt . The lake has a relatively low shoreline development of 1 .59.. Table 1 . Lake morphology for Odell Lake, Oregon . Elevation, surface (m) 145 9 Area (km2 ) 14. 4 Volume (km 3 ) 0 .5 9 Depth, maximum (m) 8 6 Depth, mean (m) 41 Shoreline length (km) 21 . 5 Shoreline development 1 .5 9 Relative depth (%) 2 . 0 1 Mean depth: max depth O . 48 Max depth: surface 0. 023 7 i 1' 0 cd o bA U 0 Q) W U O a) rd' E 06,0 4+ ~" x + a~~cd 0 a0 a) 0 b0 8 Temperature and Dissolved Oxyge n Thermal stratification in Odell Lake was well-established by th e end of June . Usually, the lake remained stratified until November whe n fall overturn occurred. In 1968, thermal stratification was evident as late as October 19. On November 26, the lake was homothermal a t 6.77 ± 0 .15 D C . During the following winter (1968-69), the lake froze over completely . From June through September, strong westerly wind s pushed warm surface water toward the east half of the lake . There it piled up, displacing the thermocline (e .g ., the thermocline at Station 3 was always three to five meters deeper than at Station 1) . As a re- sult, surface and perhaps internal seiches may have been generate d regularly. Current systems such as these could be an important facto r in the distribution of nutrients and heat energy throughout the lake . Summer heat incomes of 25, 924 g cal/cm2 and 26, 659 g cal/cm2 were computed fdi 1968 and 1969, respectively . In earlier studies of Odell Lake, teriperatures were recorded vertically near Station 1 (Averett , 1966) and Station 2 (Newcomb, 1941) (Figure 1) . The oxygen profiles at stations 1 and 3 approximated one another . During the summers of 1968 .and 1969, the concentration of dissolve d oxygen throughout the water column was essentially uniform (Figure s 2, 3) . Newcomb (1941) measured dissolved oxygen at depths of 0, 15 , 38, and 55 meters . He reported a slight difference in measurement s (i.e ., 8. 0 to 7 . 6 ppm of dissolved oxygen from the surface to maxima l 9 TEMPERATURE DISSOLVED OXYGEN pH SPECIFIC CONDUCTANCE DEPTH C mp/I mlcromho /cm at 25C meters 4 4 YZ 16 20 4 12 60 7~ }p a i t? 3f) • - 20 • 1 64 - - - JUNE 18, 968 TEMPERATURE DISSOLVED OXYGEN pH SPECIFIC CONDUCTANCE DEPTH mg/I micramhos/cm at 23C meters 4 s 12 16 20 I • ! 12 6O 70 5 0 110 30 60 t0 12 .